US2236088A - Refrigerating apparatus - Google Patents

Description

March 25, 1941.

R.- W. DOEG REFRIGERATING APPARATUS 5 Sheets-Sheet 1 Filed April 24, 1939 ATTORNEY.

March 25, 1941. R. w. DOEG REFRIGERATING APPARATUS Filed April 24, 1939 .5 Sheets-Sheet 2 ZWMZM M I .0 f7 0 w w E r 1 1 a 6 12/ w W Q M W "w ,7 M w U0 8 w; Jm F AT'TORNEY.

, March 25, 1941. R w 'DQEG 4 2,236,088

REFRIGERATING APPARATUS P41, P M Doze,

ATTORNEY.

March 25, 1941. R w DQEG 2,236,088

REFRIGERATING Arrmuus Filed April 24, 1939 5 Sheets-Sheet 5 Patented Mar. 25, 1941 umreo STATES PATENT OFFICE 2,236,088 REFRIGERATING APPARATUS poration of Maryland Application April at.

9 Glaims.

This invention relates to refrigerating apparatus and more particularly to compressors employed in such apparatus.

It is an object of the present invention to pro vide an improved system for unloading a refrigerant compressor which enables initiation of compressor operation under no working load conditions and to operate for a period of time before assuming the working load and to provide improved means for sealing certain unloading mechanism to avoid noises and to provide proper sealing surfaces in the unloading system.

Another object is to provide an improved system of lubricating and sealing unloading mechanism of a refrigerant compressor.

Another object of the invention is to provide an improved motor compressor unit of the hermetically sealed type wherein the motor and compressor is assembled as a unitary structure and,

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings.

in the drawings:

Fig. 1 is a side elevational view of the motorcompressor schematically illustrated with a refrigerating system:

i Fig. 2 is a longitudinal cross sectional view of the invention:

Fig. 3 is a cross sectional tially on line 3-3 of Fig. 2: I g

Fig. i is a cross sectional viewtaken substan tially on line i-l of Fig. 2:

Fig. 5 is a cross sectional tially on line il-ii of Fig, 2;

Fig. 6 is a cross sectional. view taken substantially on line ii-li of Fig, 4';

Fig. 7 isxacross sectionalview takensubstan tially on. line ll' of Fig. 6;

Fig. 8 is across sectional vi view taken substanview taken substan ew taken substanstantially on-line t-tof Fig. i; Fig. 9 is a vertical cross sectional view of an unloading device used in'the invention;

Fig. 10 is a longitudinal cross sectional view of a modified form of theinvention;

Fig. 11 isa cross sectional view .taken substantially on line ll-ll of Fig. .10;

Fig. 12 is a' longitudinal cross sectional view of another modified form of the invention;

Fig. 13 is a cross sectionalview taken substantially on line i i-43 of Fig. 12; i

Fig, 1a is a vertical cross sectional view of a 5 modified formof unloading device;

Detroit, Kelvinator Corporation,

Mich, assignor to Nash- Detroit, Mic a cor- 1939, Serial No. 269,598

(Cl. 23fl-5B) Fig. 15 is a longitudinal cross sectional view of a further modified form of the invention;

Fig. 16 is a cross sectional view taken substantially on line iii-4t of Fig. 12, with parts broken away and parts shown in'section;

Fig. 17 is a longitudinal cross sectional view of a still further modified form of the invention;

Fig. 18 is a cross sectional view taken substantially on line lt lt of Fig. 17, with parts broken away and parts shown in section.

Referring to the drawings, 20 designates a sealed casing for a motor-compressor unit of a refrigerant system. The gaseous refrigerant is drawn from the evaporator 23 through a conduit it to the casing fill where it is compressed and delivered by a conduit 2% to a condenser 2i and the liquid refrigerant is then conducted to a high side float it, and then to the evaporator 23. The operation of the motor-compressor unit is controlled by a thermostatically operated switch (not shown) connected to and responsive to the change of temperature of the evaporator 23.

The motor-compressor casing 20 is divided by an. integral partition ti and a removable partitlon 39 into a motor compartment it, a compressor compartment ill and a high pressure compartment it. The casing it is sealed by end walls 3% and ii. The partition 32 is provided with a bearing iii, and a bearing 38 is provided in the removable partition 39 in which a shaft ls journalled. The partition it is removably secured to the casing by bolts it. A rotor M of an electric motor is amazed to the reduced portion ilt of the shaft that extends into compartment ft, and a stator it is securely fixed to the casing it and in alignment with the rotor. A look nut 't'l is screwed onto the shaft ttiandengages an end of the rotor and forces the rotor against a collar it, which bears against a shoulder it on the shaft th for locking the rotor to the shaft.

A hollow bolt has screw-threaded engage ment with an end oi the shaft tit, and a nut ti carried by the bolt and engaging an end or the bearing 3% cooperates with the collar Min limiting any longitudinal movement. of the shatttt in its bearings. l I

Within the compartmentil, a cylinder ii! is formed in the wall of the casing 2t, and partition W. The cylinder bore extends through the casing ill, and is provided with a valve plate tit and a cylinder head tit mounted on the outer wall oi the casing. A piston till is mounted for reciprocation in the cylinder and has a connecting rod it pivoted thereto, and which is connected to an eccentric it on the shaft it.

the casing 28 and compartment 21. A filter 68 is attached to the coupling for filtering the gas eous refrigerant discharged into passage 61.

Passage 61 communicates with a passage 18 extending from the motor compartment 26 and a spring controlled valve 12 is interposed between these passages for preventing any backflow of oil and refrigerant to the evaporator. The refrigerant is drawn from compartment 26, see Fig. 8, through a filter 15 in a passage 16 located in the partition 32 and is delivered to the intake chamber 11, in the cylinder head 64, see Fig. 7, where a reed valve 19 controls the delivery of refrigerant to the cylinder 6I. A valve 82 of the cylinder head controls communication between exhaust port 8| on the valve plate and chamber 84, and from which chamber 84 the refrigerant is delivered into passages 85 and 86 formed in partition 39 and conducted to a chamber 81 formed in a housing 98 of the compartment 28. The housing 90 is secured to the bearing 38 by bolts 9I and encloses the end of the shaft 35. A tube 92 delivers the refrigerant from chamber 81 to the high pressure compartment 28 where it passes through the outlet H8 to the condenser.

A shield 93 having a central opening 94 therein is located within the housing 98 and is held in place by clamping the turned down edges 95 thereof between the bearing 38 and the housing 90 for forming an auxiliary chamber 89 around the bolt 53 and shaft 35. The bolt 53 has a passage 96 formed therein which communicates with a passage 98 extending throughout the length of the shaft 35. By providing the shield 93 the agitationof the separated oil in the housing 98 by the rotation of the bolt 53 is reduced to a minimum and thus the oil will flow through opening 94 in the shield and into the passages 96 and 98 without producing foam.

In the starting of the compressor, when powered by a motor of the low starting torque, the compressor should be required to do as little Work as possible, and thus there should be a balance of pressures on both sides of the piston until the motor has gained sufficient speed to operate the piston as a pump. To accomplish this there is provided an unloader valve I08 which consists of .a housing I8I having a sliding weight I02. A needle valve 183 is attached to said weight by pin I04 and located in a passage I85. A seat I86 is arranged to cooperate with the needle valve I 83. A spring I08 seated on the bottom of housing IOI presses against .a shoulder I81 of the weight I02 and urges said weight toward a plug I09 of the housing. Slots II8 see Fig. 2, are provided in the weight I82 to permit with passage I05 the further flow of refrigerant into the compartment v26 when the .needle valve I03 is unseated, and also to prevent any dashpot action when the needle valve is seatedand the housing is filled with oil In the drawing the needle valve is seated, thus closing the valve, which will be the position taken by the valve when the motor has gained suflicient momentum so that by centrifugal force the weight will move outwardly against the compression of the spring I08. During the idle period or at the start of the cycle the spring I88 will force the weight I82 toward the plug I09 thus unseating the valve I 03 and permitting a free flow of gaseous refrigerant or an equalization of pressures between thecompartments 26 and 28 by way of passages 96 and 98. However upon the seating of valve I83 communication between the compartments will be broken and thus there will be a withdrawal of evaporated refrigerant from the evaporator 23 through the conduit 24, passages 61 and 18 into the compartment 26. From the compartment 26 the refrigerant and any oil absorbed thereby will be drawn by suction through passage 16, which passage is located adjacent the bottom of compartment 26, into the intake chamber 11 past reed valve 19 into the cylinder 6|. The piston will force the compressed refrigerant under pressure past the valve 82 into the chamber 84 through the passages 85 and 86 into the chamber 81. Upon reaching this chamber 81 the oil and refrigerant will separate due to the change of velocity in passing from a small orifice 86 into an enlarged chamber 61, and the refrigerant will pass through the tube 92 into the compartment 28 from which it will eventually flow through the outlet II8 t the condenser 2I. The oil upon being separated will be collected in the bottom of chamber 81 until there is a sufficient quantity to overflow through opening 94 to enter the passages 96 and 98 to furnish a supply of oil to aid in sealing the unloading valve I88 against gas leakage between the compartments during the operation of the compressor.

In order to provide for a quiet and eflicient operation and the lubrication of shaft 35 in bearing 38 a passage I I2 is formed in the wall 39 which passage communicates, through a screen I I I with the high pressure compartment 28 within which a quantity of oil is maintained. The compressed refrigerant supplied to compartment 28 will exert a pressure on the body of oil causing it to be forced up the passage I I2 to the shaft. As the bearing 38 opens into the high pressure chamber 81 and the lower pressure compartment 21 the oil will work towards the compartment 21 and thereby provide for a quiet bearing as well as reducing wear to a. minimum and this oil will further aid in sealing against gas leakage along the bearing.

A predetermined amount of oil is maintained in compartment 21 to lubricate the frictional surfaces of the connecting rod, piston and eccentric. These parts when in motion will splash the oil upwardly, to be caught in trough II mounted on partition 32, and delivered from said trough to lubricate shaft 35 and bearing 33 by means of passageway II 1.

In Figs. and 11 there is shown a modified form of the invention in which the mechanism of motor, compressor and unloader are assembled together as a unit and slid into the casing I58 and sealed by an end plate I51 that is weldanism is assembled on a casting I52 which includes a motor support section I53, a compressor housing I54 and a bearing section I55. Shaft I51 is journalled in the bore I56 formed in the bearing section I55, and it is also journalled in a bearing I58 formed in a plate I59, which plate serves as part of the compressor housing I54 to form the compression chamber I 68. The casting I52 is so arranged within the casing I 58 as to provide therewith a high pressure compartment I62 and a low pressure compartment I6I; said last named compartment having the shaft I51 extending therein and a rotor I63 operatively connected thereto. A stator I64is fixedly secured to section I 53 of casting I52 in compartment I6I and cooperates with .the rotor. An eccentric I62 is formed integral with the shaft I51 upon which ed, soldered, press fitted or the like. The mechrecl'procates a piston H55 in a cylinder lB'I, which there is connected a. connecting rod I65 which cylinder is formed in the casting I52. The cylinder is provided with a valve plate let, an inlet reed valve ltd, an exhaust valve H0, an exhaust port l'lb formed in'the cylinder head tilt.

The evaporated gaseous refrigerant is admitted into the motor compartment iBl from the conduit it through the inlet port i'lt where it is drawn through conduit l'it into passage ill iormed in the partition wall past the reed valve ltd into the cylinder @511, where it is compressed and discharged through valve ill] and port tit,

hill

dill

Elli

dill

into the cylinder head. it! I. A passage lit formed in the cylinder wall conducts the compressed reirigerant to a chamber ill of a housing at, and similar to chamber 37, shown in Fig. 2. The relrigerant is discharged from chamber ll'l through tube lllt into the high pressure compartment ltd.

it passage ht for unloading the compressor durlug the starting period extends from chamber ill through shaft it! to an unloader. valve ilt ailhired to the end of shaft ltl in the motor conipartment lti. This unloader valve and the op-' oration thereof are the same as shown in Figs. 2 and ii.

Lubrication oi the bore ltd is provided through a passage lllll formed in the housing ltd that opens below the oil level iii in the compartment Mill. The oil will be forced up the passage to lubricate the shalt ili'l in the bore lbt by the compressed refrigerant oi the compartment. "the oil oi the compartment also acts as a cooling agent for the compressor which is partiallr surrounded thereby. Upon the rotation at the cocentric lltt in the compartment ltd oil will he splashed therein some or which will be caught in the poclret ltd formed in the plate ltd item which it will be delivered by a passage flit to the hearing lhll. v

in the modification shown in Fig. 12 the motor, compressor and unload-er device are all assembled as a unit upon a casting tit which is slid into a shell till that is hermetically sealed by an end plate lit by welding, soldering or the hire. ll central wall or partition lit l'ormed intear-ally with the casting tit serves to divide the shell into a low pressure compartment ill and a high pressure compartment tit. Formed can trallv of the wall tilt is a bearing lit for iournailing a shalt iii. A rotor illllt oi an electric motor is hired to the reduced portion lit at the shaft tilt and a stator f ith is fixedly secured to the casting to function with the rotor. Formed on the shait til within the low pressure compartment till is a cranlr tilt and journalled to said crank is a connecting rod lit, to which a piston lid is joined by wrist pin hit. The piston reciprocates within a cylinder tit .iormed integrally with the casting tit, and a compression chamber is iormed between the piston and a valve supporting plate till. it cylinder head till is mounted on the open end of cylinder ltd.

liteirigerant gas is deliveredto the compartrnent ill by conduit 20, through an lnlet'coupling an and conduit 212. A valve lit in conduit tit prevents any baclrflow through the conill duit. i l tube 233 extends above oil level of compartment ill and conducts the refrigerant to intalre chamber 2M, A reed valve 2% controls the flow-of refrigerant gases from chamber lltll into the cylinder 232 for compression, while the discharge valve 245 controls the flow of com" pressed gases from the cylinder. A passage 2% refrigerant therefrom. A conduit M1 is con- .nected to the casting no and communicates with passage Mt for conducting the refrigerant to the compartment tit.

The shaft Mi is provided with an axial passage 98 which provides communication between the compartments ill and tit, as. previously described. The unloader valve lull, in this instance is provided with a chamber Mt formed in a wall thereoi which has communication with the needle valve ltt by a duct ttt. An opening tit is formed in the wall or the unloader through which the tube or conduit t ll extends for discharging the compressed refrigerant and oil into the chamber ltd, where the oil may be separated from the refrigerant and the refrigerant allowed to escape into the compartment tit, and conducted through the outlet thi in the casing to a condenser.

Whenever the oil level t lt in compartment til rises above the tube ltd, oil will be drawn in with the refrigerant and discharged from tube till into chamber till where due to the change oi velocity the oil particles will separate and ilow into passage tit! while the refrigerant gases will pass through opening tilt into the high pressure compartment lit. The oil will be stored in passage thll where it is held by centrifugal force to seal the valve of the unloader mechanism against the flow or refrigerant during the opera tion of the compressor.

Peripheral grooves tilt formed on the shalt ill for lubricating purposes are supplied with oil by a tube tilt connected to hearing tit and extending below the oil level iltt in the compartment tilt. an annular groove tilt is formed on the shaft. tit and communicates with arterial passage tilt formed in the shaft til. it. passage tilt l'ormed in the connecting rod lit has communicatlon with passage ltd for conducting luhricant to the crank, connecting rod and wrist pin. 7

Figs. 15 and 16 are similar to the other struc tures including a reciprocating compressor tilt mounted on a casting ti t which has a sliding fit within the casing l ht. The casting supports a stator winding tilt of an electric motor, within whichls a rotor hill. The rotor lilll drives the compressor through a shaft till journalled in a bearing till of-the casting. The casting divides the casing into a low pressure compartment lid in which the compressor is located, and a high pressurecompartment an unloading valve tilt is connected to the shaft within the compartment tit and has communication with an axial passage in the shaft till. A tube tit through i which the compressed refrigerant is discharged from the compressor Still extends into the high pressure compartment tit and conforms somewhat to the circular contour or the casing, and terminates in a downwardly extending portion for discharging the refrigerant and oil into a reservoir formed on the upper surface of the bearing lit. .The tube is preferably enlarged or has a' greater diameter as at Mt ted to the compressor through inlet connection 321 into compartment 3|8 where the refrigerant with some particles of oil will be drawn through the tube 340 into the compressor 3l6 by the action of the piston. The compressed gases will be discharged through tube 328 into enlarged tube 330 and will be delivered to reservoir 335 along with the particles of oil that have entered the tube 330 through the openings 334. Upon reaching the reservoir the oil and gas will separate due to the change of velocity and the oil will drop to the bottom of the reservoir 335 where it will fiow through passage 331 to the peripheral groove 33!! where it will provide lu-' brication for the shaft and bearing 3I2 and then into the passage 326 to the unloader 324, for forming a seal therefor. Thus the oil will provide for quiet and efiicient lubrication and operation and will also serve as a seal for preventing gas leakage. During the unloading of the compressor, the refrigerant in compartment 322 will flow together with the oil in the reservoir 335 through the passages 33! and 326, and to the unloader valve 324 and into compartment 3l8 for balancing the pressure in the compartments.

An oil passage 342 formed in the bearing 3I2 and web of the casting 3 forms a communication between the oil reservoir 33l and the grooves 343 formed on shaft 3H]. Due to the pressure in compartment 322 oil will be forced through passage 342 to the grooves 343 from whence it will tend to work towards the low pressure compartment 3l8 thus eventually flowing into passage 344 which passage will deliver the oil to the compressor for lubricating purposes.

The modified forms shown in Figs. 17 and 18 are similar to the other structures including a reciprocating compressor 416 mounted on a casting 4| 4 which has a sliding fit within the eas-- ing I50. The casting supports a stator winding 420 of an electric motor, within which is a rotor 45 l. The rotor 45I drives the compressor through a shaft 4I0 journalled in a bearing 4l2 of the casting. The casting divides the casing into a high pressure compartment 422 and a low pressure compartment 8 in which the compressor '4 I 6 is located. The compressor head 446 and part of the compressor 4| 6 are submerged below the oil level 445 maintained in the compartment for cooling purposes. An unloading valve 424 is connected to the shaft within the compartment 4! and has communication with an axial passage- 426, in the shaft 4I0. A tube 428 through which the compressed refrigerant is discharged from the compressor head 446 extends into the high pressure compartment 422 and conforms somewhat to the circular contour of the casing, and terminates in a downwardly extending portion for discharging the refrigerant and oil into a reservoir 435 formed on the upper surface of the bearing 4| 2. The tube is preferably enlarged or has a greater diameter as at 430 throughout a greater portion of its length, which allows for expansion of the refrigerant. The tube is provided with perforations or openings 434 for admitting lubricant or oil, located in the compartment at 43l, thereto, and which is carried by the compressed refrigerant to the reservoir.

Evaporated gaseous refrigerant will be admitted to the compressor through inlet connection 421 into compartment M8 where the refrigerant with some particles of oil will be drawn through the tube 440 into the compressor M6 by the action of the piston. The compressed gases will be delivered to the compressor head 446 and then discharged through tub 428 into enlarged tube 430 and will be delivered to the reservoir 435 along with the particles of oil that have enteredthe tube 430 through th openings 434. Upon reaching the reservoir the oil and gas will separate due to the change of velocity and the oil will drop to the bottom of the reservoir 435 when it will flow through passage 43'! to the peripheral groove 439 where it will provide lubrication for the shaft and bearing 4l2 and then into the passage 426 to the unloader 424 for forming a seal therefor. Thus the oil will provide for quiet and eflicient lubrication and operation and will also serve as a seal for preventing gas leakage. During the unloading of the compressor, the refrigerant in compartment 422 will flow together with the oil in the reservoir 435 through the passages 43'! and 426 to the unloader valve 424 and into compartment M8 for balancing the pressures in the compartments.

An oil tube 442 extends from below the oil level 43l of compartment 422 through bearing M2 to the peripheral grooves 443 formed on shaft 4H), Due to the pressure in compartment 422 oil will be forced through tub 442 to the grooves 443 from whence it will tend to work towards the low pressure compartment 418 thus eventually flowing into passage 444 which passage will deliver the oil to the compressor for lubricating purposes.

Although only a preferred form of the invention has been illustrated, and that form described in detail, it will be apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim: 1. A refrigerating apparatus comprising a casing having a partition for dividing the easing into a high pressure compartment and a low pressure compartment, a shaft jou-rnalled in said partition, a motor and a compressor in said casing and connected to said shaft whereby the compressor is operated upon the rotation of the motor, means for conducting high pressure refrigerant from said compressor to the high pressure compartment, an oil reservoir in said high pressure compartment, means forming communication with said oil reservoir and shaft whereby th oil of the reservoir may be supplied to the shaft by the pressure of the refrigerant in said high pressure compartment.

2. In a refrigerating apparatus, comprising a casing having a high pressure, a low pressure and a compressor compartment, a motor mounted in said low pressure compartment, a compressor mounted in said compressor compartment, partitions in said casing between said casing between said compartments, shaft bearings formed in said partitions, a shaft mounted in said bearings connected to said motor and compressor and extending into said high pressure compartment, a housing in said high pressure compartment enclosing an end of said shaft, a centrifugal unloader valve mounted on the opposite end of said shaft and located in said low pressure compartment, said shaft having a passage therethrough forming a communication between the high and low pressure compartments during the idle and star-ting periods of the motor-compressor for equalizing the pressure of said compartments, means for conducting low pressure refrigerant from the 10W pressur compartment to said comto the compressor, means for conducting the compressed refrigerant from said compressor to said chamber Where any oil in said refrigerant may be separated therefrom, said oil flowing from said chamber by means of a passage to said valve for sealing the valve against gas leakage between the compartments.

9. In a refrigerating apparatus comprising a casing adapted to contain lubricant, a motor and 10 a compressor positioned in the casing, a support- RALPH W. DOEG.

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